1. Field
The present invention relates to a GaN transistor and a method of fabricating the same. More particularly, the present invention relates to a GaN transistor, in which a bonding pad structure is improved to be appropriate to a wire bonding process or a back-side via-hole forming process to enhance adhesive force, thereby increasing a yield and improving reliability, and a method of fabricating the same.
2. Discussion of Related Art
Recently, a GaN transistor has been widely used as an ultrahigh frequency high-power device used in a radar for a war machine and a transceiver for a mobile communication base station. The high-power GaN transistor is generally mounted in a transceiver in a packaged form in a unit device form, or in a form of a Monolithic Microwave Integrated Circuit (MMIC).
In this case, for the packaging or the interconnection, a drain electrode and a gate electrode are mostly wire-bonded, and a source pad is connected by wire-bonding or a back-side via-hole forming process, and thus a bonding pad for a connection with an external device is fabricated in the transistor or the MMIC. The bonding pad in the GaN transistor or the GaN MMIC in a batch process is generally formed by plating gold on a gate metal (nickel/gold) or a first metal interconnection (titanium/gold).
However, there is a case where adhesive force between the bonding pad and a wafer is poor according to a process condition, and during the wire bonding or the back-side via-hole forming process, the bonding pad is detached or the pad is separated during an operation, so that a life of a chip may be decreased.